1. Field of the Invention
The present invention relates to a communication apparatus, a transmission line communication chip, and a communication method.
2. Description of the Related Art
Nowadays, power line communication (PLC) that performs communication using a power line is known. In the PLC, if different communication methods exist and apparatuses of a plurality of communication methods are used simultaneously without synchronization, each of such apparatuses serves as an interference source for other apparatuses. Thus, it is necessary to change the plurality of methods depending on time division, but apparatuses using power lines do not communicate with each other and thus, time division information is transmitted/received by detecting presence of carriers of signals of other apparatuses and connecting simple 1-bit signals. Since it is necessary to output the 1-bit signal after being synchronized by each method, a technique to synchronize signals according to predetermined reference timing is used. In the case of PLC, for example, a definite reference called a zero-cross point of AC power supply is known and signals are synchronized with reference to the zero-cross point.
Japanese Patent Application Laid-Open No. 2007-19662